Some country has n cities. 
The government has decided to electrify all these cities.
At first, power stations in k different cities were built. 
The other cities should be connected with the power stations 
via power lines. For any cities i, j it is possible to build
a power line between them in cij roubles.
The country is in crisis after a civil war, so the government decided to build only a few power 
lines. Of course from every city there must be a path along the lines to 
some city with a power station. Find the minimum possible cost to build all necessary power lines.  
Input
The first line contains integers n and k (1 ≤ k ≤ 
n ≤ 100). The second line contains k different integers that are the 
numbers of the cities with power stations. The next n lines 
contain an n × n table of integers {cij} (0 ≤ cij ≤ 105). 
It is guaranteed that cij = cji, cij > 0 for i ≠ j, cii = 0.
Output
Output the minimum cost to electrify all the cities.
Sample
| input | output | 
|---|
| 4 2
1 4
0 2 4 3
2 0 5 2
4 5 0 1
3 2 1 0
 | 3
 | 
Problem Author: Mikhail Rubinchik
Problem Source: Open Ural FU Championship 2013